That question comes up because on Sunday, Mr. Trump took a shot at CEOs, saying on CBS’s “Face the Nation” that chief executive pay in America is so high that it is “a total and complete joke.”

In the free enterprise system, company boards of directors should curtail excessive payouts, but they don’t, Trump added. That’s because CEOs maneuver their cronies onto boards and quid pro quos ensue.

Billionaire Trump has benefited quite handsomely from aspects of the US economic system, of course. All those CEOs and hedge-fund managers and other members of the 0.1 percent are his peers. (He might not agree with that. He’d probably say most of those folks are relatively poor, compared with himself and his own riches.)

But that hasn’t stopped him from striking a populist tone on some economic issues. He’s talked about raising taxes on top earners. In particular, he’s scoffed at the carried-interest exemption, which allows some hedge-fund managers and other big earners to pay a lower, capital-gains rate on their annual income.

Trump’s not exactly a modern Franklin D. Roosevelt, the wealthy populist labeled a class traitor in his own time. FDR took a radical approach to government, top to bottom. He portrayed big government as the savior of the United States. Trump, the outsider politician, is pretty much doing the opposite.

Whether Trump’s tax proposals are populist in a narrower sense depends on their total effect. Jeb Bush would also do away with the carried-interest exemption, for instance. But Mr. Bush’s tax package would also cut other rates paid by the rich, leading critics to call it trickle-down economics in populist clothing.

That said, it’s obvious by now that Trump is running as a very different kind of Republican. There are elements of Huey Long-like populism in his political appeal. The Donald has become the choice of many voters who have lost all faith in the establishment institutions of American life, from Washington to big business to the media.

These voters are the “crazy buts,” according to National Journal’s veteran political reporter Ron Fournier. That means they explain their support for Trump by saying, “He may be crazy, but ..."

“But he’s punishing the establishment. But he’s driving the media nuts. But he says what I can’t say,” writes Mr. Fournier, in examples of how Trumpians complete that sentence.

CEOs may not like him, politically speaking. But voters with relatively less education do. Education levels are among the most striking differences in support for Trump, according to a new ABC News poll. In this just-released survey, 40 percent of Republican leaners without a college degree back Trump. Of those with a college degree, 19 percent support the real estate mogul/reality TV star.

Trump even scores well with Republicans on the classic “understands the problems of people like me” question. He may boast about his ex-supermodel wife, his personal plane, and his billions. Still, according to a recent Washington Post poll, 53 percent of GOP voters say he has enough populist understanding that he understands their concerns.